Field of the Invention
The invention relates to a power-control device, and more particularly to a power-control device with a performance monitor circuit which is capable of generating a supply voltage to a target processing module to serve as its operation voltage by monitoring the operation state of the target processing module.
Description of the Related Art
Electronic devices consume power when processors perform operations, and so power control is important, especially in mobile devices. When a processor in performs a specific operation, a lower supply voltage is expected, for reducing power consumption. Generally, one dynamic voltage-frequency scaling (DVFS) table consists of a plurality of operation frequencies and a plurality of corresponding operation voltages. For a batch of chips, an operation voltage applied to the batch of chips can be found in one DVFS table on a specific operation frequency. However, among one batch of chips, the chips may have different frequency-voltage characteristics, and even the frequency-voltage characteristic of one chip can vary between different operation states. Thus, when a fixed DVFS table is applied for all of the chips in the same batch, power consumption may not be reduced for the chips that can achieve the same expected operation frequency on lower voltages.